No, no, no!!!!! Never, ever pollute your mac with a completely unneeded antivirus application!
Do some research and you will soon understand that installing antivirus applications on a Mac mac will do nothing to improve your safety and may instead introduce vulnerabilities, performance issues, and instability that you never had before.
While researching the issue, ignore any article that urges that there are Mac viruses and vulnerabilities that make macs more vulnerable than ever. Every single one of these FUD articles are written by security software companies that will benefit from misleading typical users into believing their bull crap!
Keep your Mac secure by updating software as necessary, not using untrusted WiFi networks, not installing Flash or Java, and NOT installing any unnecessary or untrusted software such as security software for the Mac!